Rare-Earth Doping by Ion Implantation and Related Techniques

1993 ◽  
Vol 301 ◽  
Author(s):  
Ian G. Brown
Keyword(s):  
Rare Earth ◽  
Ion Implantation ◽  
Rare Earths ◽  
High Energy ◽  
Ion Source ◽  
Low Energy ◽  
Vacuum Arc ◽  
Rare Earth Doping ◽  
Metal Plasma ◽  
Wide Range

ABSTRACTSome metal plasma techniques have been developed that provide a convenient means for the doping of semiconductor hosts with rare-earths. These plasma and ion beam tools are based on the application of vacuum arc discharges for the formation of dense rare-earth plasmas which then can be used in a number of ways for doping and otherwise introducing the rare-earths into substrate materials. At the low energy end of the spectrum, the streaming metal plasma can be used for the deposition of thin films, and if more than one plasma source is used then of multilayer structures also. Or by building the vacuum-arc rare-earth plasma generator into an ion source configuration, high current ion beams can be produced for doing high energy ion implantation; alternatively the substrate can be immersed in the streaming rare-earth plasma and by using appropriately phased high voltage substrate pulsing and pulsed plasma generation, plasma immersion ion implantation can be done. Between these two limiting techniques – low energy plasma deposition and high energy ion implantation – a spectrum of hybrid methods can be utilized for rare earth doping. We've made a number of plasma and ion sources of this kind, and we've doped a wide range of substrates with a wide range of rare-earths. For example we've implanted species including Sc, Y, La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er and Yb into host materials including Si, GaAs, InP and more. The implantation dose can range from a low of about 1013 cm−2 up to as high as about 1017 cm−2, and the ion energy can be varied from a few tens of eV up to about 200 keV. Here we review these vacuum-arc-based plasma methods for rare-earth doping, describing both the tools and techniques that are available and the applications to which we've put the methods in our laboratory.

New Developments in Metal Ion Implantation by Vacuum Arc Ion Sources and Metal Plasma Immersion

1995 ◽  
Vol 396 ◽  
Author(s):  
I.G. Brown ◽  
A. Anders ◽  
S. Anders ◽  
M.R. Dickinson ◽  
R.A. MacGill ◽  
...  
Keyword(s):  
Surface Modification ◽  
Ion Implantation ◽  
Metal Ion ◽  
Arc Discharge ◽  
High Energy ◽  
Ion Source ◽  
Plasma Sheath ◽  
Vacuum Arc ◽  
Large Area ◽  
Metal Plasma

AbstractIon implantation by intense beams of metal ions can be accomplished using the dense metal plasma formed in a vacuum arc discharge embodied either in a vacuum arc ion source or in a ‘metal plasma immersion’ configuration. In the former case high energy metal ion beams are formed and implantation is done in a more-or-less conventional way, and in the latter case the substrate is immersed in the plasma and repetitively pulse-biased so as to accelerate the ions at the high voltage plasma sheath formed at the substrate. A number of advances have been made in the last few years, both in plasma technology and in the surface modification procedures, that enhance the effectiveness and versatility of the methods, including for example: controlled increase of the ion charge states produced; operation in a dual metal-gaseous ion species mode; very large area beam formation; macroparticle filtering; and the development of processing regimes for optimizing adhesion, morphology and structure. These complementary ion processing techniques provide the plasma tools for doing ion surface modification over a very wide parameter regime, from ‘pure’ ion implantation at energies approaching the MeV level, through ion mixing at energies in the ∼1 to ∼100 keV range, to IBAD-like processing at energies from a few tens of eV to a few keV. Here we review the methods, describe a number of recent developments, and outline some of the surface modification applications to which the methods have been put.

Low Energy Ion Implantation / Deposition as a Film Synthesis and Bonding Tool

1993 ◽  
Vol 316 ◽  
Author(s):  
André Anders ◽  
Simons Anders ◽  
Ian G. Brown ◽  
Igor C. Ivanov
Keyword(s):  
Ion Implantation ◽  
Plasma Deposition ◽  
Surface Film ◽  
Ion Beam ◽  
Low Energy ◽  
Vacuum Arc ◽  
Metallic Component ◽  
Wide Range ◽  
Film Synthesis ◽  
Atomic Mixing

ABSTRACTWe describe a novel means for the production of atomically-bonded thin films of a wide range of materials. The technique is a plasma and ion beam method involving synthesis of the desired surface film by plasma deposition and the simultaneous atomic mixing of the film into the substrate by low energy ion implantation from the surrounding plasma. Vacuum-arc-produced metal plasma is used for the metallic component of the film and gases can be added to form compound films. Multiple plasma generators can be used, and films of single metals, alloys, ceramics and multilayers can be formed. By repetitively pulse biasing the substrate during plasma deposition, the growing film is subjected to energetic ion bombardment, and direct and recoil ion implantation is induced. The depositing film is thereby atomically mixed to the substrate as it is formed. The films are atomically smooth, can be anywhere from a few monolayers to microns in thickness, and the interface or mixed transition zone can be tailored. Here we outline the basic plasma physics of the method and describe a number of novel surfaces which have been formed with excellent properties.

A Study of the Structural, Mechanical and Tribological Properties of Ti-Al-N Coatings Post-Treated by Carbon Implantation

2009 ◽  
Vol 75 ◽  
pp. 7-12
Author(s):  
P.W. Shum ◽  
Zhi Feng Zhou ◽  
K.Y. Li
Keyword(s):  
Friction Coefficient ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
High Energy ◽  
Ion Source ◽  
Hard Coatings ◽  
Vacuum Arc ◽  
Metal Vapour ◽  
X Ray ◽  
Mechanical And Tribological Properties

Carbon ion implantation has often been considered as an additional method to further improve the wear, corrosion and oxidation resistance of hard coatings on tools or machine parts. The present research investigates the effect of carbon implantation on the structural and mechanical properties of the sputter-deposited solid solution Ti-Al-N coatings. The carbon implantation was carried out by using metal vapour vacuum arc ion source (MEVVA) with solid cathode at energies of 5 and 50 keV, and a dose of 6×1017 atoms cm-2. The mechanical and the microstructure properties of the implanted layer were identified by a variety of analytic techniques, such as nano-indentation, x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD) etc. Additionally, the wear performance of the samples was evaluated by a typical ball-on-disk tribometer in dry conditions. The results showed that the coatings with high energy carbon implantation exhibited an enhanced hardness. The improved hardness could be attributed to the formation of TiC phase, as indicated in XPS. In the sliding tests, the coatings with the post-treatment of carbon implantation showed an improved tribological property in terms of friction coefficient and wear rate. The friction coefficient could be reduced from 0.6 to 0.1. The coatings had ten-fold better wear resistance than the coating without ion implantation.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

COMPARISON OF WEAR RESISTANCE MECHANISMS OF DIE STEEL IMPLANTED WITH C AND Mo IONS

2007 ◽  
Vol 14 (03) ◽  
pp. 517-520
Author(s):  
M. F. CHENG ◽  
J. H. YANG ◽  
X. D. LUO ◽  
T. H. ZHANG
Keyword(s):  
Wear Resistance ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
Resistance Mechanisms ◽  
Ion Source ◽  
Vacuum Arc ◽  
H13 Steel ◽  
Die Steel ◽  
X Ray

Mo and C ions extracted from a metal vapor vacuum arc ion source were implanted into the surface of die steel (H13) to compare the wear resistance mechanisms of the implanted samples, respectively. The concentration depth profiles of implanted ions were measured using Rutherford backscattering spectroscopy and calculated by a code called TRIDYN. The structures of the implanted steel were observed by X-ray photoelectron spectroscopy and grazing-angle X-ray diffraction, respectively. It was found that the conventional heat-treated H13 steel could not be further hardened by the subsequent implanted C ions, and the thickness of the implanted layer was not an important factor for the Mo and C ion implantation to improve the wear resistance of the H13 steel. Mo ion implantation could obviously improve the wear resistance of the steel at an extraction voltage of 48 kV and a dose of 5 × 1017 cm -2 due to formation of a modification layer of little oxidation with Mo 2 C in the implanted surface.

Surface Modification of Electromagnetic Railgun Components

1993 ◽  
Vol 316 ◽  
Author(s):  
M. A. Otooni ◽  
A. Graf ◽  
C. Dunham ◽  
Ian Brown ◽  
Xiang Yao
Keyword(s):  
Electron Microscopy ◽  
Metal Ion ◽  
High Energy ◽  
Ion Source ◽  
Vacuum Arc ◽  
Sufficient Evidence ◽  
Wear Properties ◽  
Implantation Energy ◽  
Rutherford Back Scattering ◽  
Spark Erosion

ABSTRACTCopper and aluminum used for rail and armature materials in electromagnetic railgun systems undergo severe degradation during the EM gun operation. The extent of this degradation is especially severe in guns operated at high energy levels or designed for repeated firings. In an effort to improve surface properties of the copper rail, armature, and sabot materials, the technique of metal ion implantation using a vacuum arc ion source has been employed. Preliminary tests have been conducted to identify the best implant species to improve spark erosion resistance, scratch resistance and hardness. The implanted species included Al, Ti, Cr, Ni, Ta, Ag, and W. The implantation energy range and dose varied between 100–180 KeV and 0.4 to 2 × 1017 cm-2, respectively . Several analytical techniques were also used to assess the effect of implanted species. These included Rutherford Back Scattering (RBS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Microhardness Measurements, Spark Erosion and Scratch Testing. It has been tentatively concluded that Ta and Ni implantation of the copper rail substantially improve wear and inhibit arc erosion. There is also sufficient evidence to indicate that implantation of the aluminum armature with Cr and Ta, involving two stages of implantation, will also improve its mechanical and wear properties.

scholarly journals Conceptual study on parasitic low-energy RI beam production with in-flight separator BigRIPS and the first stopping examination for high-energy RI beams in the parasitic gas cell

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
T Sonoda ◽  
I Katayama ◽  
M Wada ◽  
H Iimura ◽  
V Sonnenschein ◽  
...  
Keyword(s):  
High Energy ◽  
Ion Source ◽  
Low Energy ◽  
Laser Ion Source ◽  
Gas Cell ◽  
Beam Production ◽  
Expected Benefits ◽  
Conceptual Study ◽  
Ri Beam

Abstract An in-flight separator performs the important role of separating a single specific radioactive isotope (RI) beam from the thousands of RI beams produced by in-flight fission as well as projectile fragmentation. However, when looking at ``separation'' from a different viewpoint, more than 99% of simultaneously produced RI beams are just eliminated in the focal plane slits or elsewhere in the separator. In order to enhance the effective usability of the RIKEN in-flight separator BigRIPS, we have been developing an innovative method: parasitic laser ion source (PALIS), which implements parasitic low-energy RI beam production by saving eliminated RI beams during BigRIPS experiments. In this paper, we present the expected benefits and feasibility for the PALIS concept and the results of the first stopping examination for high-energy RI beams in the gas cell.

The optical spectrum of UVLED excitation using NTC nanometer particles to replace rare earth doping

MRS Advances ◽  
2019 ◽  
Vol 4 (33-34) ◽  
pp. 1895-1904
Author(s):  
Lihong Su ◽  
Kan Chen ◽  
Yongqiang Liu ◽  
ZiAo Zou ◽  
Lihua Su
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Optical Spectrum ◽  
Low Cost ◽  
Rare Earth Ions ◽  
Rare Earth Doping ◽  
Phosphor Material ◽  
Light Emitting ◽  
Luminescence Efficiency ◽  
Nickel Copper

Abstract:Ultraviolet light-emitting diodes (UVLEDs) with phosphor materials have considerable advantages over traditional illumination devices. Doping with rare earth ions can modify the optical spectrum of phosphor materials, but rare earths are very expensive. Thus, replacing rare earths with a common material would provide a great potential for the wide application in the future. In this study, we discovered that a novel type of semiconductor nanometre powder, namely manganese cobalt nickel copper oxide (MCNC), is able to emit blue-green wavelength spectrum when exited by 365-400nmUVLED. In addition, MCNC shows less attenuation of luminescence efficiency than other UVLED phosphor materials doped with rare earths with temperature increase. It is thus concluded that MCNC is a promising low-cost material to replace rare earths to adjust the optical spectrum wavelength of UVLED. This is the first time that nano-scale MCNC is reported to possess the property to change the optical spectrum wavelength of UVLED. This provides a new mechanical and nanometer phosphor material without rare earth doping to shift the wavelength spectrum.

scholarly journals Formation of Buried Epitaxial Si-Ge Alloy Layers in Si Crystal by High Dose Ge ION Implantation

1991 ◽  
Vol 235 ◽  
Author(s):  
Kin Man Yu ◽  
Ian G. Brown ◽  
Seongil Im
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Lattice Mismatch ◽  
Solid Phase ◽  
Metal Vapor ◽  
Ion Source ◽  
Vacuum Arc ◽  
High Dose ◽  
Solid Phase Epitaxy ◽  
Ion Channeling

ABSTRACTWe have synthesized single crystal Si1−xGex alloy layers in Si <100> crystals by high dose Ge ion implantation and solid phase epitaxy. The implantation was performed using the metal vapor vacuum arc (Mevva) ion source. Ge ions at mean energies of 70 and 100 keV and with doses ranging from 1×1016 to to 7×1016 ions/cm2 were implanted into Si <100> crystals at room temperature, resulting in the formation of Si1−xGex alloy layers with peak Ge concentrations of 4 to 13 atomic %. Epitaxial regrowth of the amorphous layers was initiated by thermal annealing at temperatures higher than 500°C. The solid phase epitaxy process, the crystal quality, microstructures, interface morphology and defect structures were characterized by ion channeling and transmission electron microscopy. Compositionally graded single crystal Si1−xGex layers with full width at half maximum ∼100nm were formed under a ∼30nm Si layer after annealing at 600°C for 15 min. A high density of defects was found in the layers as well as in the substrate Si just below the original amorphous/crystalline interface. The concentration of these defects was significantly reduced after annealing at 900°C. The kinetics of the regrowth process, the crystalline quality of the alloy layers, the annealing characteristics of the defects, and the strains due to the lattice mismatch between the alloy and the substrate are discussed.

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